# Calculate leakage in 1" PVC with known pressure.
**URL:** https://boards.straightdope.com/t/calculate-leakage-in-1-pvc-with-known-pressure/753600
**Category:** Factual Questions
**Created:** [May 1, 2016, 3:40pm UTC](https://boards.straightdope.com/t/calculate-leakage-in-1-pvc-with-known-pressure/753600 "2016-05-01T15:40:26Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@nodsirrah](https://boards.straightdope.com/u/nodsirrah)
#### Post date: [May 1, 2016, 3:40pm UTC](https://boards.straightdope.com/t/calculate-leakage-in-1-pvc-with-known-pressure/753600/1 "2016-05-01T15:40:26Z")
How do I calculate water volume leakage in a buried 1" schedule 20 PVC (140 feet).
I can isolate the line and use a pressure gauge to see how much the pressure differential loss I have over a 24 hour period of time.
I turn off the water before cold weather but there is no easy way to drain it since there is little elevation change from one end to the other.
Thanks
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### Author:  [@TriPolar](https://boards.straightdope.com/u/TriPolar)
#### Post date: [May 1, 2016, 4:24pm UTC](https://boards.straightdope.com/t/calculate-leakage-in-1-pvc-with-known-pressure/753600/2 "2016-05-01T16:24:40Z")
Do you have city water with a meter? Easiest way is to monitor the meter with all other outlets shut. I assume this is for lawn sprinkling or other irrigation. Why do you need to measure the loss? If it’s a lot you really need to find and fix the leak, if it’s a small amount it’s still providing water to the plants unless you’re in a situation where it just drains away underground.
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### Author:  [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)
#### Post date: [May 1, 2016, 4:44pm UTC](https://boards.straightdope.com/t/calculate-leakage-in-1-pvc-with-known-pressure/753600/3 "2016-05-01T16:44:18Z")
> [@nodsirrah](#):
>
> How do I calculate water volume leakage in a buried 1" schedule 20 PVC (140 feet).
> I can isolate the line and use a pressure gauge to see how much the pressure differential loss I have over a 24 hour period of time.
> I turn off the water before cold weather but there is no easy way to drain it since there is little elevation change from one end to the other.
> Thanks
If it holds pressure at all after 24 hours it’s probably not leaking. Losing a couple tablespoons would drop it to 0. If you want to know if a line is leaking pressure test it with an air compressor.
The volume of water on a leaking pressurized line is rather irreverent. It’s unlikely to remain consistent and will likely get worse.